Propanol 14 0.4392
Butanol 12 0.4176
Pentanol13.95 0.4810
Hexanol12.2 0.3448
Table 4: Shows the average temperature change and the average change in mass of burner for each of the fuels. The averages were based on five trials.
PropanolTheoretical Heat of Reaction:
Bonds Broken Bonds Formed Type of Bond Bond Energy (KJ/mole) Number of Bonds Total (KJ/mole) Type of Bond Bond Energy (KJ/mole) Number of Bonds Total (KJ/mole)
C-H 412 7 2884 C=O 802 6 4812
C-C 348 2 696 H-O 463 8 3704
O=O 496 5 2480 C-O 366 1 366 O-H 463 1 463 Total 6889 Total 8516
Table 5: Shows the theoretical heat change in enthalpy for Propanol
From the above results, the theoretical change in enthalpy can be calculated. The following calculation is done by Hess’s law:
∆H=∑Energy of broken bonds-∑Energy of bonds made=6889-8516= -1627 KJ/MoleExperimental Heat of Reaction:
Energy Produced: q=mC∆T=100 ×4.18 ×14q=5852JEnergy Produced per mole:
One mole of Propanol is 60.1 grams; therefore the energy produced per mole can be calculated:
Energy produced per mole= 60.10.4392 ×5852=800785.9745 J/moleEnergy produced per mole=800.7859745 KJ/molePercentage Error:
Percentage Error= Theoretical Heat of Combustion-Experimental Heat of CombustionTheoretical Heat of Combustion×100=1627-800.78597451627 ×100Percentage Error=50.78 %ButanolTheoretical Heat of Reaction:
Bonds Broken Bonds Formed Type of Bond Bond Energy (KJ/mole) Number of Bonds Total (KJ/mole) Type of Bond Bond Energy (KJ/mole) Number of Bonds Total (KJ/mole)
C-H 412 9 3708 C=O 802 8 6416
C-C 348 3 1044 H-O 463 10 4630
O=O 496 6 2976 C-O 366 1 366 O-H 463 1 463 Total 8557 Total 11046
Table 6: Shows the theoretical heat change in enthalpy for Butanol
From the above results, the theoretical change in enthalpy can be calculated. The following calculation is done by Hess’s law:
∆H=∑Energy of broken bonds-∑Energy of bonds